[Qemu-devel] [PATCH 05/34] linux-user: Support for restarting system calls for ARM targets

[Timothy E Baldwin]

Signed-off-by: Timothy Edward Baldwin <t.e.baldwi...@members.leeds.ac.uk>
---
 linux-user/aarch64/syscall.h |  2 ++
 linux-user/arm/syscall.h     |  2 ++
 linux-user/main.c            | 47 +++++++++++++++++++++++++++-----------------
 linux-user/signal.c          | 10 +++++-----
 4 files changed, 38 insertions(+), 23 deletions(-)

diff --git a/linux-user/aarch64/syscall.h b/linux-user/aarch64/syscall.h
index dc72a15..bc1f01b 100644
--- a/linux-user/aarch64/syscall.h
+++ b/linux-user/aarch64/syscall.h
@@ -11,3 +11,5 @@ struct target_pt_regs {
 #define TARGET_MINSIGSTKSZ       2048
 #define TARGET_MLOCKALL_MCL_CURRENT 1
 #define TARGET_MLOCKALL_MCL_FUTURE  2
+
+#define TARGET_USE_ERESTARTSYS 1
diff --git a/linux-user/arm/syscall.h b/linux-user/arm/syscall.h
index 3844a96..38c925a 100644
--- a/linux-user/arm/syscall.h
+++ b/linux-user/arm/syscall.h
@@ -48,3 +48,5 @@ struct target_pt_regs {
 #define TARGET_MINSIGSTKSZ 2048
 #define TARGET_MLOCKALL_MCL_CURRENT 1
 #define TARGET_MLOCKALL_MCL_FUTURE  2
+
+#define TARGET_USE_ERESTARTSYS 1
diff --git a/linux-user/main.c b/linux-user/main.c
index 99fe591..9653155 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -820,15 +820,20 @@ void cpu_loop(CPUARMState *env)
                             break;
                         }
                     } else {
-                        env->regs[0] = do_syscall(env,
-                                                  n,
-                                                  env->regs[0],
-                                                  env->regs[1],
-                                                  env->regs[2],
-                                                  env->regs[3],
-                                                  env->regs[4],
-                                                  env->regs[5],
-                                                  0, 0);
+                        abi_ulong ret = do_syscall(env,
+                                                   n,
+                                                   env->regs[0],
+                                                   env->regs[1],
+                                                   env->regs[2],
+                                                   env->regs[3],
+                                                   env->regs[4],
+                                                   env->regs[5],
+                                                   0, 0);
+                        if (ret == -TARGET_ERESTARTSYS) {
+                            env->regs[15] -= env->thumb ? 2 : 4;
+                        } else if (ret != -TARGET_QEMU_ESIGRETURN) {
+                            env->regs[0] = ret;
+                        }
                     }
                 } else {
                     goto error;
@@ -1010,6 +1015,7 @@ void cpu_loop(CPUARMState *env)
 {
     CPUState *cs = CPU(arm_env_get_cpu(env));
     int trapnr, sig;
+    abi_long ret;
     target_siginfo_t info;
 
     for (;;) {
@@ -1019,15 +1025,20 @@ void cpu_loop(CPUARMState *env)
 
         switch (trapnr) {
         case EXCP_SWI:
-            env->xregs[0] = do_syscall(env,
-                                       env->xregs[8],
-                                       env->xregs[0],
-                                       env->xregs[1],
-                                       env->xregs[2],
-                                       env->xregs[3],
-                                       env->xregs[4],
-                                       env->xregs[5],
-                                       0, 0);
+            ret = do_syscall(env,
+                             env->xregs[8],
+                             env->xregs[0],
+                             env->xregs[1],
+                             env->xregs[2],
+                             env->xregs[3],
+                             env->xregs[4],
+                             env->xregs[5],
+                             0, 0);
+            if (ret == -TARGET_ERESTARTSYS) {
+                env->pc -= 4;
+            } else if (ret != -TARGET_QEMU_ESIGRETURN) {
+                env->xregs[0] = ret;
+            }
             break;
         case EXCP_INTERRUPT:
             /* just indicate that signals should be handled asap */
diff --git a/linux-user/signal.c b/linux-user/signal.c
index 0186147..c8f288b 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -1402,7 +1402,7 @@ long do_rt_sigreturn(CPUARMState *env)
     }
 
     unlock_user_struct(frame, frame_addr, 0);
-    return env->xregs[0];
+    return -TARGET_QEMU_ESIGRETURN;
 
  badframe:
     unlock_user_struct(frame, frame_addr, 0);
@@ -1908,7 +1908,7 @@ static long do_sigreturn_v1(CPUARMState *env)
         send_sig(SIGTRAP, current, 1);
 #endif
     unlock_user_struct(frame, frame_addr, 0);
-    return env->regs[0];
+    return -TARGET_QEMU_ESIGRETURN;
 
 badframe:
     force_sig(TARGET_SIGSEGV /* , current */);
@@ -2033,7 +2033,7 @@ static long do_sigreturn_v2(CPUARMState *env)
     }
 
     unlock_user_struct(frame, frame_addr, 0);
-    return env->regs[0];
+    return -TARGET_QEMU_ESIGRETURN;
 
 badframe:
     unlock_user_struct(frame, frame_addr, 0);
@@ -2086,7 +2086,7 @@ static long do_rt_sigreturn_v1(CPUARMState *env)
         send_sig(SIGTRAP, current, 1);
 #endif
     unlock_user_struct(frame, frame_addr, 0);
-    return env->regs[0];
+    return -TARGET_QEMU_ESIGRETURN;
 
 badframe:
     unlock_user_struct(frame, frame_addr, 0);
@@ -2118,7 +2118,7 @@ static long do_rt_sigreturn_v2(CPUARMState *env)
     }
 
     unlock_user_struct(frame, frame_addr, 0);
-    return env->regs[0];
+    return -TARGET_QEMU_ESIGRETURN;
 
 badframe:
     unlock_user_struct(frame, frame_addr, 0);
-- 
2.1.4